Direct drive unit removal system and associated methods

ABSTRACT

Described herein are embodiments of systems and methods for the removal of a direct drive unit (DDU) housed in an enclosure, such as a direct drive turbine (DDT) connected to a gearbox for driving a driveshaft connected to a pump for use in a hydraulic fracturing operations.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. Non-Provisional application Ser. No. 15/929,924, filed May 29, 2020, titled “DIRECT DRIVE UNIT REMOVAL SYSTEM AND ASSOCIATED METHODS,” which claims the benefit of and priority to U.S. Provisional Application No. 62/899,975, filed Sep. 13, 2019, titled “TURBINE REMOVAL SYSTEM,” the entire disclosures of each of which are incorporated herein by reference.

BACKGROUND OF THE DISCLOSURE

This disclosure relates to embodiments of systems and methods for the removal and/or positioning of a direct drive unit housed in an enclosure, such as a direct drive turbine (DDT) when connected to a gearbox for driving a driveshaft, which, in turn, may be connected to a pump such as for use in a hydraulic fracturing system.

Traditional fracturing pumping fleets have had fuel supplied from a single fuel source. In such units, when a unit runs low on fuel (for example diesel), that unit is shutdown while another stand by unit is brought in, refueled, and then put into service. Some inefficiencies included in this process are that the unit once low on primary fuel must be stopped, refueled while another unit is simultaneously being introduced into its place to make up for the loss of the pumping power that the unit provides. This may affect the pumping performance during a section as well as requiring human intervention to perform the refueling, lining up suction and discharge valves. This may require multiple personnel to relay back the information so the process is performed in the correct series of steps. Using a single fuel source also limits the ability for the fracturing fleet to make it continuously through a section when low on fuel which results in delays in pumping completion.

In addition, in cases where the unit needs to be taken offline for maintenance or replacement, significant disassembly is required to remove the unit from its enclosure and to install a replacement unit, potentially resulting in excessive downtime. In some cases, the entire trailer and enclosure need to be removed from the site so a new, fully equipped trailer may be moved into place.

Accordingly, it may be seen that a need exists for more efficient ways of accessing the drive units for maintenance purposes and/or replacement with minimum disruption to the system operations and the surrounding equipment. The present disclosure addresses these and other related and unrelated problems in the art.

SUMMARY OF THE DISCLOSURE

According to one embodiment of the disclosure, a method of removing a direct drive unit (DDU) housed in an enclosure. The DDU includes a gearbox and a turbine engine connected to the gearbox for driving a driveshaft connected to a pump for use in high-pressure, high-power hydraulic fracturing operations. The method may include accessing the enclosure. The enclosure contains air inlet ducting connected to the turbine engine and air exhaust ducting connected to the turbine engine. The method may further include disconnecting the turbine engine from the air inlet ducting, disconnecting the turbine engine from at least one fuel line, disconnecting the gearbox from the driveshaft, disconnecting the turbine engine from an at least one exhaust flange connected to the air exhaust ducting, and operating a DDU positioner assembly to position the DDU for withdrawal from the enclosure, and removing the DDU from the enclosure.

According to another embodiment of the disclosure, a direct drive unit (DDU) positioner assembly is disclosed for positioning a DDU housed in an enclosure for removal from the enclosure. The DDU includes a gearbox and a turbine engine connected to the gearbox for driving a driveshaft connected to a pump for use in high-pressure, high-power hydraulic fracturing operations. The DDU positioner assembly may include a plurality of longitudinal rails extending in a longitudinal direction along the central axis of the DDU and a plurality of lateral rails extending in a lateral direction transverse to the longitudinal direction. The DDU positioner assembly may further include a platform slidably connected to the plurality of lateral rails. The plurality of longitudinal rails may be mounted on the platform and the DDU may be slidably connected to the longitudinal rails. The DDU may be movable in the longitudinal direction along the longitudinal rails and the platform may be movable in the lateral direction along the lateral rails.

According to yet another embodiment of the disclosure, a direct drive unit (DDU) positioner assembly is disclosed for positioning a DDU housed in an enclosure for removal from the enclosure. The DDU includes a gearbox and a turbine engine connected to the gearbox for driving a driveshaft connected to a pump for use in high-pressure, high-power, hydraulic fracturing operations. The DDU positioner assembly may include a platform connected to a support of the gearbox and mounted on an enclosure base of the enclosure. The enclosure base may have a plurality of lubrication grooves for facilitating sliding movement of the platform relative to the enclosure base. The DDU positioner assembly may include a lubricator to convey lubricant to the lubrication grooves. The platform may be fixedly attached to the enclosure base by one or more fasteners during operation of the DDU and in slidable engagement with the enclosure base upon removal of the one or more fasteners.

Those skilled in the art will appreciate the benefits of various additional embodiments reading the following detailed description of the embodiments with reference to the below-listed drawing figures. It is within the scope of the present disclosure that the above-discussed aspects be provided both individually and in various combinations.

BRIEF DESCRIPTION OF THE DRAWINGS

According to common practice, the various features of the drawings discussed below are not necessarily drawn to scale. Dimensions of various features and elements in the drawings may be expanded or reduced to more clearly illustrate the embodiments of the disclosure.

FIG. 1A is a schematic diagram of a pumping unit according to an embodiment of the disclosure.

FIG. 1B is a schematic diagram of a layout of a fluid pumping system according to an embodiment of the disclosure.

FIG. 2 is a perspective view of an enclosure for housing a direct drive unit (DDU) according to an embodiment of the disclosure.

FIG. 3 is a top plan view of the enclosure housing the DDU according to an embodiment of the disclosure.

FIG. 4 is a side elevation view of the DDU mounted on a DDU positioner assembly according to a first embodiment of the disclosure.

FIG. 5 is an end elevation view of the DDU of FIG. 4 according to a first embodiment of the disclosure.

FIG. 6A is a perspective view of the DDU of FIG. 4 in a first position according to a first embodiment of the disclosure.

FIG. 6B is a perspective view of the DDU of FIG. 6A moved to a second position according to a first embodiment of the disclosure.

FIG. 6C is a perspective view of the DDU of FIG. 6B moved to a third position according to a first embodiment of the disclosure.

FIG. 7 is a side elevation view of the DDU mounted on a DDU positioner assembly according to a second embodiment of the disclosure.

FIG. 8A is a perspective view of the DDU of FIG. 7 in a first position according to a second embodiment of the disclosure.

FIG. 8B is a perspective view of the DDU of FIG. 8A moved to a second position according to a second embodiment of the disclosure.

FIG. 8C is a perspective view of the DDU of FIG. 8B moved to a third position according to a second embodiment of the disclosure.

FIG. 9 is an enlarged detail of a portion of the DDU positioner assembly according to a second embodiment of the disclosure.

FIG. 10 is a detail of a portion of the DDU positioner assembly according to a second embodiment.

FIG. 11 is a side elevation view of the DDU mounted on a DDU positioner assembly according to a third embodiment of the disclosure.

FIG. 12A is a perspective view of the DDU of FIG. 11 in a first position according to a third embodiment of the disclosure.

FIG. 12B is a perspective view of the DDU of FIG. 12A moved to a second position according to a third embodiment of the disclosure.

FIG. 12C is a perspective view of the DDU of FIG. 12B moved to a third position according to a third embodiment of the disclosure.

Corresponding parts are designated by corresponding reference numbers throughout the drawings.

DETAILED DESCRIPTION

Generally, this disclosure is directed to a direct drive unit (DDU) positioner assembly, positioning system, removal system, and/or associated mechanisms that will allow a DDU including a gearbox and a turbine engine connected to the gearbox to be detached from surrounding equipment and removed through the side of an enclosure housing the direct drive unit. The system will allow for inspections, maintenance, or even a complete exchange of the direct drive unit with another if necessary.

FIG. 1A illustrates a schematic view of a pumping unit 11 for use in a high-pressure, high power, fluid pumping system 13 (FIG. 1B) for use in hydraulic fracturing operations according to one embodiment of the disclosure. FIG. 1B shows a typical pad layout of the pumping units 11 (indicated as FP1, FP2, FP3, FP4, FP5, FP6, FP7, FP8) with the pumping units all operatively connected to a manifold M that is operatively connected to a wellhead W. By way of an example, the system 13 is a hydraulic fracturing application that may be sized to achieve a maximum rated horsepower of 24,000 HP for the pumping system 13, including a quantity of eight (8) 3000 horsepower (HP) pumping units 11 that may be used in one embodiment of the disclosure. It will be understood that the fluid pumping system 13 may include associated service equipment such as hoses, connections, and assemblies, among other devices and tools. As shown in FIG. 1, each of the pumping units 11 are mounted on a trailer 15 for transport and positioning at the jobsite. Each pumping unit 11 includes an enclosure 21 that houses a direct drive unit (DDU) 23 including a gas turbine engine 25 operatively connected to a gearbox 27. The pumping unit 11 has a driveshaft 31 operatively connected to the gearbox 27. The pumping unit 11 includes a high-pressure, high-power, reciprocating positive displacement pump 33 that is operatively connected to the DDU 23 via the driveshaft 31. In one embodiment, the pumping unit 11 is mounted on the trailer 15 adjacent the DDU 23. The trailer 15 includes other associated components such as a turbine exhaust duct 35 operatively connected to the gas turbine engine 25, air intake duct 37 operatively connected to the gas turbine, and other associated equipment hoses, connections, etc. to facilitate operation of the fluid pumping unit 11.

In the illustrated embodiment, the gas turbine engine 25 is a Vericor Model TF50F bi-fuel turbine; however, the direct drive unit 23 may include other gas turbines or suitable drive units, systems, and/or mechanisms suitable for use as a hydraulic fracturing pump drive without departing from the disclosure. The gas turbine engine 25 is cantilever mounted to the gearbox 27 with the gearbox supported by the floor 41 of the enclosure 21. The gearbox 27 may be a reduction helical gearbox that has a constant running power rating of 5500 SHP and intermittent power output of 5850 SHP, or other suitable gearbox. It should also be noted that, while the disclosure primarily describes the systems and mechanisms for use with direct drive units 23 to operate fracturing pumping units 33, the disclosed systems and mechanisms may also be directed to other equipment within the well stimulation industry such as, for example, blenders, cementing units, power generators and related equipment, without departing from the scope of the disclosure.

FIG. 2 illustrates the enclosure 21 that houses the direct drive unit 23 in an interior space 46 of the enclosure. In one embodiment, the enclosure has access doors 45 for removal of the DDU 23 from the enclosure and/or other components within the enclosure. The enclosure 21 provides sound attenuation of the DDU 23 during operation.

As shown in FIG. 3, the direct drive unit 23 and the enclosure 21 has a longitudinal axis L1 and a lateral axis L2 transverse to the longitudinal axis. FIG. 3 illustrates a top view of the enclosure 21 with the DDU 23 shown attached to the driveshaft 31 that extends through an opening 48 in a first longitudinal end 47 of the enclosure. An air exhaust assembly 35 extends through a second longitudinal end 49 of the enclosure. The DDU 23 has a central axis CL extending in the longitudinal direction L1 that extends through the centerline of the unit and is aligned with the centerline of the driveshaft 31. The gearbox 27 includes an outlet flange 50 that is connected to the driveshaft 31. The gas turbine engine 25 has two air inlet ports 51, 53 on a respective lateral side of the central axis CL and an exhaust duct flange 54 that connects the gas turbine engine to the air exhaust assembly 35 at the longitudinal end 49 of the enclosure 21. In one embodiment, the access doors 45 are mounted on a first lateral side 55 of the enclosure 21, but the enclosure may have additional access doors on a second lateral side 57 of the enclosure, or the access doors may be positioned only on the second lateral side without departing from the scope of this disclosure. The gas turbine engine 25 may include polymer expansion joints 61, 63 connected to air inlet ports 51, 53, to facilitate the removal of the gas turbine engine from the enclosure 21. The gas turbine engine 25 may include various fuel lines, communication lines, hydraulic and pneumatic connections, and other connections or accessories needed for operation of the gas turbine engine without departing from the disclosure. Such connections may utilize quick disconnect fittings and check valves to facilitate disconnection of the gas turbine engine 25 during removal of the DDU 23 from the enclosure 21. Further, such connections such as fuel lines and hydraulic lines may run to a single bulkhead (not shown) within or near the enclosure to allow for quick disconnection by locating these connections in a common location.

FIG. 4 is a side elevation view of the DDU 23 as viewed from the lateral side 55 of the enclosure 21, with the DDU being mounted on a DDU positioner assembly or DDU positioning system 101 (FIGS. 4-6C) for positioning the DDU for withdrawal or removal from the enclosure through the access doors 45. In one embodiment, the DDU positioner assembly 101 comprises a platform 103 slidably mounted to overlie two lateral rails 105, 107 mounted to overlie the floor 41 of the enclosure 21 and extending laterally across the enclosure generally between the lateral sides 55, 57. The DDU positioner assembly 101 comprises two longitudinal rails 109, 111 mounted to overlie the platform 103 and extending in the longitudinal direction L1. The DDU 23 is slidably mounted on the longitudinal rails 109, 111 for positioning the DDU in the longitudinal direction L1. In one embodiment, the DDU positioner assembly 101 includes lateral guide rollers 115, 117 mounted on a respective lateral rail 105, 107, and longitudinal guide rollers 121, 123 mounted on a respective longitudinal rail 109, 111. The platform 103 is connected to the lateral guide rollers 115, 117 to allow slidable movement and positioning of the DDU 23 mounted on the platform in the lateral direction L2 via the lateral rails 105, 107. The longitudinal guide rollers 121, 123 are connected to a mounting base 127 of the gearbox 27 to allow slidable movement and positioning of the DDU 23 in the longitudinal direction L1 via the longitudinal rails 109, 111. In one embodiment, the DDU positioner assembly 101 includes four lateral guide rollers 115, 117 and four longitudinal guide rollers 121, 123, but more or less than eight guide rollers may be provided without departing from the scope of the disclosure. Further, more or less than two longitudinal rails 109, 111, and more or less than two lateral rails 105, 107 may be provided without departing from the scope of the disclosure. In one embodiment, the guide rollers 115, 117, 121, 123 may be a caged ball type linear motion (LM) Guide, model number SPS20LR available from THK America Inc., or any similar make or model number without departing from the scope of the disclosure. The DDU positioner assembly 101 may be equipped with locking mechanisms 128 mounted on a respective guide roller 115, 117, 121, 123. The locking mechanisms 128 may be spring loaded and will default to the locked position to allow the DDU 23 to be secured in the operating position. The locking mechanism 128 may be otherwise located on the positioning system 101 without departing from the disclosure.

Exemplary loading calculations for sizing the guide rails 105, 107, 109, 111 are shown below and are based on the Vericor TF50F turbine parameters as follows: approximate turbine weight, 1475 lbs.; approximate fuel system weight, 85 lbs.; approximate gearbox weight, 4000 lbs.; for a total approximate weight of 5559 lbs. Various other parameters may be applicable based on the make, model, and size of the gas turbine engine 25.

Because of the arrangement the direct drive unit 23 including the gas turbine engine 25 cantilever mounted onto the gearbox 27 and extending in the longitudinal direction L1 from the gearbox, there is added load put onto the rear lateral guide rollers 115 and the rear longitudinal guide rollers 121, 123 (the guide rollers mounted closest to the gas turbine engine). Accordingly, an increased load rating may be applied to the rear guide rollers 115, 121, 123 if required. The calculation of the cantilever load and the reaction forces may be calculated with the formulas shown below, which may also be used for further design and implementation of the disclosed removal mechanisms.

Maximum Reaction at the fixed end may be expressed as: R_(A)=qL.

where: R_(A)=reaction force in A (N, lb), q=uniform distributed load (N/m, N/mm, lb/in), and

L=length of cantilever beam (m, mm, in).

Maximum Moment at the fixed end may be expressed as M_(A)=−q L²/2

Maximum Deflection at the end may be expressed as δ_(B)=q L⁴/(8 E I).

where: δ_(B)=maximum deflection in B (m, mm, in).

In one embodiment, the longitudinal guide rollers 121, 123 connected to the support structure 127 of the gearbox 27 are positioned between each pair of the lateral guide rollers 115, 117 to ensure equal weight distribution over the platform 103 and to avoid cantilever loading the platform. Different configurations of platforms, sliders, rails and mounts are contemplated and considered within the scope of the disclosure. The configurations of the DDU positioner assembly 101 may vary to suit a particular DDU 23 with various alternative combinations of makes, model, and sizes of the gas turbine engine 25 and the gearbox 27.

In one embodiment, the guide rails 105, 107, 109, 111 are made from a steel composition that has been mill finished and shot blasted to protect the rail from the high heat environment within the turbine enclosure 21 and ensure strength retention under the exposed temperatures. In one embodiment, the platform 103 is constructed out of a composite material; however, other materials are contemplated and considered within the scope of the disclosure, such as but not limited to, steel or stainless steel. The guide rails 105, 107, 109, 111, platform 103, and/or other components of the DDU positioner assembly 101 may be made of various other suitable materials without departing from the scope of the disclosure.

FIGS. 6A-6B illustrate an exemplary method of removing the direct drive unit 23 from the enclosure 21 utilizing the DDU positioner assembly 101. FIG. 6A shows the DDU 23 in a first/operating position for operation with the pump 33 of the pumping unit 11. The method includes accessing the enclosure 21 and disconnecting the gas turbine engine 25 from the air inlet ducting 37. The flanges 51, 53 may be disconnected from the air inlet ducting 37 and the expansion joints 61, 63 flexed to allow separation of the DDU 23 from the air inlet ducting. The gas turbine engine 25 may be disconnected from the air exhaust ducting 35 by disconnecting the exhaust duct flange 54 from the air exhaust ducting. Corresponding hoses, piping, wiring, and cabling including fuel lines, electrical lines, hydraulic lines, control lines or any other connection that is needed for operation of the gas turbine engine 25 may also be disconnected so that the gas turbine engine is free to move without damaging any of the operational connections needed for operation of the gas turbine engine. For example, the air bleed off valve ducting may be removed from the turbine engine 25 and secured at a location free of interference with movement of the turbine engine. Alternatively, some hoses, piping, wiring, etc. may include enough slack or flexibility so that the DDU 23 may be initially moved before complete disconnection of the connections from the gas turbine engine 25 are required for removal of the DDU from the enclosure 21. The gearbox 27 may be disconnected from the driveshaft 31 by disconnecting the outlet flange 50 from the driveshaft. In one embodiment, the driveshaft 31 may be a slip-fit driveshaft allowing the driveshaft to contract to facilitate disconnection from the DDU 23. In one embodiment, the driveshaft 31 may be a 390 Series, GWB Model 390.80 driveshaft available Dana Corporation, or other suitable driveshaft. The gearbox 27 may be disconnected from any other connections needed for operation of the DDU 23 to obtain freedom of movement of the gearbox without damaging any of the operating connections.

Once the gas turbine engine 25 is disconnected from the respective connections and the gearbox 27 is disconnected from the driveshaft 31, the DDU positioner assembly 101 is operated to position the direct drive unit 23 for withdrawal from the enclosure 21. As shown in FIG. 6B, the DDU 23 is positioned in a second position where the DDU is first moved in the longitudinal direction L1 in the direction of arrow A1 by sliding the DDU along the longitudinal rails 109, 111. In one embodiment, prior to initial movement of the DDU 23 in the longitudinal direction L1, the longitudinal locks 128 associated with the longitudinal guide rollers 121, 123 must be released to allow the movement of the DDU in the longitudinal direction. After the movement of the DDU 23 in the longitudinal direction L1 to the second position, the longitudinal locks 128 may be reengaged to lock the longitudinal guide rollers 121, 123 and prevent further or additional unwanted movement of the DDU 23 along the longitudinal rails 109, 111, and the lateral locks 128 associated with the lateral guide rollers 115, 117 may be disengaged to allow lateral movement of the DDU 23. Next, the platform 103 may be moved to a third position by moving in the lateral direction L2 in the direction of arrow A2 (FIG. 6C) by sliding movement of the lateral guide rollers 115, 117 along the lateral guide rails 105, 107. The DDU 23 is mounted to the platform 103 and moves with the platform in the lateral direction L2 to the third position of FIG. 6C. As shown in FIGS. 3 and 5, the lateral guide rails 105, 107 may extend to the access doors 45 in either side 55, 57 of the enclosure 21. In some embodiments, lateral guide rail extensions 107′ (FIG. 5) may be used to extend outside of the enclosure 21 to allow the platform 103 and DDU 23 to be slid out of the enclosure onto an adjacent supporting structure or vehicle (e.g., maintenance inspection platform or other suitable structure), or the platform 103 and DDU 23 may be accessed through the access doors 45 of the enclosure 21 by a lifting mechanism (e.g., a forklift, crane, or other suitable lifting mechanism) to fully remove the DDU from the enclosure. The various method steps described herein for the method of positioning or removing the DDU 23 may be otherwise performed in an alternative order or simultaneously, or more or less steps may be used without departing from the scope of the disclosure.

FIGS. 7-10 illustrates a second embodiment of a DDU positioner assembly or system 201 for positioning the direct drive unit 23 housed in the enclosure 21. In the illustrated embodiment, the DDU 23 includes a gas turbine engine 25 and a gearbox 27 identical to the first embodiment of the disclosure, but the DDU positioner assembly 201 may be used to position a DDU that is alternatively configured without departing from the disclosure. As such, like or similar reference numbers will be used to describe identical or similar features between the two embodiments.

In one embodiment, the DDU positioner assembly 201 includes a platform 203 that supports the gearbox 27 and has a top surface 205, a bottom surface 207, two sides 208, and two ends 210. The gearbox 27 is fixedly mounted to the top surface 205 of the platform 203. The platform 203 is slidably mounted on the base 41 of the enclosure 21 with the bottom surface 207 of the platform being in slidable engagement with the floor of the enclosure. In a first or operating position (FIGS. 7 and 8A) of the direct drive unit 23, the platform 203 is fixedly attached to the base 41 by a plurality of fasteners 211. Upon removal of the fasteners 211, the platform 203 is capable of slidable movement with respect to the base 41. The platform 203 is connected to the support structure 127 of the gearbox 27 so that the drive unit 23 moves with the platform. In one embodiment, the platform 203 has two lifting openings 215, 217 extending between respective sides 208 of the platform. As shown in FIG. 7, the lifting opening 215 towards the front of the gearbox 27 (closest to the drive shaft flange 50) is spaced a first distance D1 from a centerline CT of the gearbox and the lifting opening 217 towards the rear of the gearbox (closest to the gas turbine engine 25) is spaced a second distance from the centerline CT of the gearbox, with the distance D2 being greater than the distance D2. The rear lifting opening 217 is farther from the centerline CT of the gearbox 27 because of the cantilever mounted gas turbine engine 25 that shifts the center of gravity of the DDU 23 from the centerline CT of the gearbox in the longitudinal direction toward the gas turbine engine. The platform 203 may be otherwise configured and/or arranged without departing from the scope of the disclosure.

In one embodiment, the DDU positioner assembly 201 includes a lubricator or lubrication system 221 (FIG. 9) to convey lubricant (e.g., grease or other suitable lubricant) from a lubricant reservoir 244 to a location between the bottom surface 207 of the platform 201 and the base 41 of the enclosure. The DDU positioner assembly 201 includes a lubrication portion 225 (FIG. 10) of the base 41 below the platform 203. As shown in FIG. 10, the portion 225 of the base 41 includes a plurality of lubrication grooves 227. The lubrication grooves 227 are in fluid communication with the lubricator 221 so that the lubricator provides lubricant to the grooves to facilitate sliding engagement between the platform 203 and the portion 225 of the base 41. The lubricator 221 includes a source of lubricant 244, tubing 243, and other required components (e.g., pump, controls, etc.) for delivering the lubricant to the lubrication portion 225 at a sufficiently high pressure for lubricant to fill the grooves 227 of the lubrication portion 225. In one embodiment, the lubricator 221 may be an automatic lubricator such as a model TLMP lubricator available from SKF Corporation, or the lubricator may be any other suitable lubricator including other automatic lubricators or manual lubricators without departing from the scope of the disclosure. In one embodiment, the lubrication portion 225 of the base 41 is an integral portion with the base or the floor of the enclosure 21, but the lubrication portion 225 may be a separate pad or component that is mounted between the base and the platform without departing from the disclosure. The lubricator 221 may be mounted inside the enclosure 21 or at least partially outside the enclosure without departing from the scope of the disclosure.

In one embodiment, the DDU positioner assembly 201 includes drive fasteners 241 mounted at one end 210 of the platform 203. In the illustrated embodiment, the drive fasteners 241 include a bracket 245 mounted to the floor 41 of the enclosure 21 and an impact screw 247 operatively connected to the bracket and the platform 203. The drive fasteners 241 may have other components and be otherwise arranged without departing from the disclosure. Further, more or less than two drive fasteners 241 may be provided without departing from the disclosure.

FIGS. 8A-9 illustrate an exemplary method of removing the DDU 23 from the enclosure 21 utilizing the DDU positioner assembly 201 of the second embodiment. The method is similar to the method of the first embodiment, in that the gas turbine engine 25 is disconnected from the air inlet ducting 37, the air exhaust ducting 35, and from other corresponding connections and components in a similar manner as discussed above for the first embodiment so that the gas turbine engine is free to move without damaging any of the operational connections and components needed for operation of the gas turbine engine. Further, the gearbox 27 is disconnected from the driveshaft 31 in a similar manner as the first embodiment, so that the DDU 23 has clearance for movement in the longitudinal direction L1 without interference with the driveshaft.

FIG. 8A shows the direct drive unit 23 in the first/operating position. Once the gas turbine engine 25 is disconnected from the respective components and connections and the gearbox 27 is disconnected from the driveshaft 31 and any other connections, the DDU positioner assembly 201 is operated to position the DDU 23 for withdrawal from the enclosure 21. First, the fasteners 211 fixedly attaching the platform 203 to the base 41 are removed. The lubricator 221 is operated to convey lubricant to the lubrication grooves 227 of the lubrication portion 225 of the base 41. After a sufficient amount of lubrication is located between the platform 203 and the lubrication portion 225 of the base 41, the drive fasteners 241 may be operated to move the platform 203 in the longitudinal direction L1 to a second position (FIG. 8B). As the impact screws 247 of the drive fasteners 241 are turned, the platform 203 is slid in the longitudinal direction L1 in the direction of arrow A3 (FIG. 8B). The lubricant provided in the lubrication grooves 227 and between the lubrication portion 225 and the bottom surface 207 of the platform reduces the sliding friction and allows the rotation of the impact screws 247 in the bracket 245 to advance the platform in the direction of arrow A3. The platform 203 is moved in the direction of arrow A3 a sufficient amount to allow access to the lifting openings 215, 217 by a lifting mechanism (e.g., forklift) 261 (FIG. 8C). The lifting mechanism 261 may include a forklift or other lifting mechanism that may access the interior 46 of the enclosure through the enclosure access doors 45. The lifting mechanism 261 is inserted into the lifting openings 215, 217 of the platform 203, and the DDU 23 is lifted and/or slid in the direction of arrow A4. The lifting mechanism 261 may move the DDU 23 to the third position (FIG. 8C), or transfer the DDU onto an adjacent supporting structure or vehicle (e.g., maintenance inspection platform or other suitable structure), or completely remove the platform 203 and DDU 23 from the enclosure. The various method steps described herein for the method of positioning or removing the DDU 23 by operating the DDU positioner assembly 201 may be otherwise performed in an alternative order or simultaneously, or more or less steps may be used without departing from the scope of the disclosure.

FIGS. 11-12C illustrate a third embodiment of a DDU positioner assembly or system 301 for positioning the direct drive unit 23 housed in the enclosure 21. In the illustrated embodiment, the DDU 23 includes a gas turbine engine 25 and a gearbox 27 identical to the first and second embodiments of the disclosure, but the DDU positioner assembly 301 may be used to position a DDU that is alternatively configured without departing from the disclosure as will be understood by those skilled in the art. The DDU positioner assembly 301 is generally similar to the DDU positioner assembly 201 of the second embodiment, except the drive fasteners 241 have been removed and an actuator 341 is added to the DDU positioner assembly of the third embodiment. As such, like or similar reference numbers will be used to describe identical or similar features between the second and third embodiments.

As shown in FIG. 11, the DDU positioner assembly 301 includes the actuator 341 that has a first end 345 connected to the base 41 of the enclosure 21 and a second end 347 connected to the end 210 of the platform 203. In one embodiment, the actuator 341 is a hydraulic cylinder that has a piston rod 351 that is extendible from a cylinder body 349 upon operation of the actuator. The actuator 341 may be controlled by a manual control valve or the actuator may be configured for remote operation by connection to corresponding automated control valves. In the illustrated embodiment, one actuator 341 is shown, but the DDU positioner assembly 301 may include more than one actuator without departing from the scope of the disclosure. Further, the actuator 341 may be otherwise located for attachment to the platform 203 without departing from the scope of the disclosure.

FIGS. 12A-12C illustrate an exemplary method of removing the DDU 23 from the enclosure 21 utilizing the DDU positioner assembly 301 of the second embodiment. The method is similar to the method of the utilizing the DDU positioner assembly 201 of the second embodiment, in that the gas turbine engine 25 is disconnected from the air inlet ducting 37, the air exhaust ducting 35, and from other corresponding connections and components in a similar manner as discussed above for the first embodiment so that the gas turbine engine is free to move without damaging any of the operational connections and components needed for operation of the gas turbine engine. Further, the gearbox 27 is disconnected from the driveshaft 31 in a similar manner as the first embodiment, so that the DDU 23 has clearance for movement in the longitudinal direction L1 without interference with the driveshaft. Also, the DDU positioner assembly 301 of the third embodiment includes the lubricator 221 (FIG. 9) for providing lubrication to lubrication grooves 227 of the lubrication portion 225 of the base 41 to facilitate sliding of the platform 203 in the longitudinal direction L1, so that the DDU positioner assembly of the third embodiment operates in a similar manner as the DDU positioner assembly 201 of the second embodiment.

FIG. 12A shows the direct drive unit 23 in the first/operating position. Once the gas turbine engine 25 is disconnected from the respective components and connections, and the gearbox 27 is disconnected from the driveshaft 31 and any other connections, the DDU positioner assembly 301 is operated to position the DDU 23 for withdrawal from the enclosure 21. First, the fasteners 211 fixedly attaching the platform 203 to the base 41 are removed. The lubricator 221 is operated to convey lubricant to the lubrication grooves 227 of the lubrication portion 225 of the base 41. After a sufficient amount of lubrication is located between the platform 203 and the lubrication portion 225 of the base 41, the actuator 341 may be operated to move the platform 203 in the longitudinal direction L1 to a second position (FIG. 12B). The extension of the piston rod 351 of the actuator 341 exerts a force on the platform 203 to slide the platform in the longitudinal direction L1 in the direction of arrow A3 (FIG. 12B). The lubricant provided in the lubrication grooves 227 and between the lubrication portion 225 and the bottom surface 207 of the platform reduces the sliding friction and allows the actuator 341 to advance the platform in the direction of arrow A3. As with the previous embodiment, the platform 203 is moved in the direction of arrow A3 a sufficient distance to allow access to the lifting openings 215, 217 by a lifting mechanism (e.g., forklift) 261 (FIG. 8C). The lifting mechanism 261 may include a forklift or other lifting mechanism that may access the interior 46 of the enclosure through the enclosure access doors 45. The lifting mechanism 261 is inserted into the lifting openings 215, 217 of the platform 203, and the DDU 23 is lifted and/or slid in the direction of arrow A4. Prior to moving the platform 203 in the direction of arrow A4, the actuator 341 may be disconnected from the platform (FIG. 12C) with the first end 347 of the actuator being separated from the platform and the second end 345 of the actuator remaining attached to the floor 41 of the enclosure. Alternatively, the second end 345 of the actuator 341 may be disconnected from the floor 41 of the enclosure and the first end 341 of the actuator may remain attached to the platform 203, or both ends of the actuator may be disconnected and the actuator removed without departing from the enclosure.

The lifting mechanism 261 may move the DDU 23 to the third position (FIG. 12C), or transfer the DDU onto an adjacent supporting structure or vehicle (e.g., maintenance inspection platform or other suitable structure), or completely remove the platform 203 and DDU 23 from the enclosure. The various method steps described herein for the method of positioning or removing the DDU 23 by operating the DDU positioner assembly 301 may be otherwise performed in an alternative order or simultaneously, or more or less steps may be used without departing from the scope of the disclosure.

Having now described some illustrative embodiments of the disclosure, it should be apparent to those skilled in the art that the foregoing is merely illustrative and not limiting, having been presented by way of example only. Numerous modifications and other embodiments are within the scope of one of ordinary skill in the art and are contemplated as falling within the scope of the disclosure. In particular, although many of the examples presented herein involve specific combinations of method acts or system elements, it should be understood that those acts and those elements may be combined in other ways to accomplish the same objectives. Those skilled in the art should appreciate that the parameters and configurations described herein are exemplary and that actual parameters and/or configurations will depend on the specific application in which the systems and techniques are used. Those skilled in the art should also recognize or be able to ascertain, using no more than routine experimentation, equivalents to the specific embodiments of the disclosure. It is, therefore, to be understood that the embodiments described herein are presented by way of example only and that, within the scope of any appended claims and equivalents thereto; the embodiments of the disclosure may be practiced other than as specifically described.

Furthermore, the scope of the present disclosure shall be construed to cover various modifications, combinations, additions, alterations, etc., above and to the above-described embodiments, which shall be considered to be within the scope of this disclosure. Accordingly, various features and characteristics as discussed herein may be selectively interchanged and applied to other illustrated and non-illustrated embodiment, and numerous variations, modifications, and additions further may be made thereto without departing from the spirit and scope of the present disclosure as set forth in the appended claims. 

What is claimed is:
 1. A direct drive unit (DDU) positioner assembly for positioning a DDU housed in an enclosure for removal from the enclosure, the DDU including a gearbox and a turbine engine connected to the gearbox for driving a driveshaft connected to a pump for use in high-pressure, high-power hydraulic fracturing operations, the DDU positioner assembly comprising: a plurality of longitudinal rails extending in a longitudinal direction along a central axis of the DDU; a plurality of lateral rails extending in a lateral direction transverse to the longitudinal direction; and a platform slidably connected to the plurality of lateral rails and having the plurality of longitudinal rails mounted thereon so that the DDU slidably connects to the longitudinal rails when positioned thereon, the DDU being movable in the longitudinal direction along the longitudinal rails, and the platform being movable in the lateral direction along the lateral rails.
 2. The DDU positioner assembly of claim 1, further comprising a plurality of lateral guide rollers slidably connecting the platform to a respective lateral rail of the plurality of lateral rails and a plurality of longitudinal guide rollers to slidably connect the DDU to a respective longitudinal rail of the plurality of longitudinal rails.
 3. The DDU positioner assembly of claim 2, wherein the plurality of longitudinal guide rollers is positioned longitudinally between the plurality of lateral guide rollers.
 4. The DDU positioner assembly of claim 3, wherein the platform is mounted to overlie the plurality of lateral guide rollers, and wherein the plurality of longitudinal rails is mounted to overlie the platform.
 5. The DDU positioner assembly of claim 4, wherein the plurality of longitudinal guide rollers is configured to connect to the gearbox when positioned adjacent thereto.
 6. The DDU positioner assembly of claim 4, further comprising a plurality of locking mechanisms for locking the platform in a fixed position on the plurality of lateral rails and the plurality of longitudinal rails.
 7. The DDU positioner assembly of claim 2, wherein the platform is configured to connect to a support of the gearbox when positioned adjacent thereto, and the turbine engine is mounted to the gearbox and extends in the longitudinal direction from the gearbox.
 8. A direct drive unit (DDU) positioner assembly for positioning a DDU housed in an enclosure for removal from the enclosure, the DDU including a gearbox and a turbine engine connected to the gearbox for driving a driveshaft connected to a pump for use in high-pressure, high-power, hydraulic fracturing operations, the enclosure having an enclosure base and a plurality of lubrication grooves positioned in the enclosure base, the DDU positioner assembly comprising: a platform configured to connect to a support of the gearbox when positioned adjacent thereto and mount on the enclosure base, the enclosure base having the plurality of lubrication grooves for facilitating sliding movement of the platform relative to the enclosure base; and a lubricator to convey lubricant to the lubrication grooves, the platform being configured to fixedly attached to the enclosure base by a plurality fasteners during operation of the DDU and in slidable engagement with the enclosure base upon removal of the plurality of fasteners.
 9. The DDU positioner assembly of claim 8, wherein upon removal of plurality of fasteners from the enclosure base, the platform is slidable on the enclosure base in the direction of the lubrication grooves, wherein the platform comprises a plurality of lift openings for access by a lifting mechanism, the plurality of lift openings being offset from a centerline of the gearbox when the platform is connected to the enclosure base, wherein the lift openings comprise a first lift opening and a second lift opening, the first lift opening being spaced apart from the centerline of the gearbox by a first distance, the second lift opening being spaced apart from the centerline of the gearbox by a second distance, the second distance being greater than the first distance, and wherein the second lift opening is positioned closer to the turbine engine than the first lift opening.
 10. The DDU positioner assembly of claim 9, further comprising one or more drive fasteners in contact with the platform, the one or more drive fasteners being operable to initiate sliding movement of the platform along the enclosure base to position the lift openings for access by the lifting mechanism, wherein the platform comprises an upper surface supporting the gearbox, a lower surface in slidable engagement with the base, two sides, and two ends, the lift openings extending in a lateral direction through the sides of the platform, and wherein the one or more drive fasteners are operatively connected to one of the ends of the platform and are operable to initiate sliding movement of the platform in the longitudinal direction.
 11. The DDU positioner assembly of claim 8, wherein the enclosure base includes a lubrication portion of a floor of the enclosure, the lubrication portion having the lubrication grooves and being operably connected to the lubricator, and wherein the enclosure base comprises a removable pad secured to the floor of the enclosure, the removable pad having the lubrication grooves fluidly connected to the lubricator.
 12. The DDU positioner assembly of claim 10, further comprising one or more actuator operatively connected to the platform, the one or more actuator being operable to initiate sliding movement of the platform along the enclosure base to position the lift openings for access by the lifting mechanism, wherein the platform includes an upper surface supporting the gearbox, a lower surface in slidable engagement with the base, two sides, and two ends, the lift openings extending in a lateral direction through the sides of the platform, and wherein the one or more actuator is operatively connected to one of the ends of the platform and is operable to initiate sliding movement of the enclosure base in the longitudinal direction. 